1) You must use the hive to transport between servers. If you die, you will respawn on the server you transferred to.
2) The only way to go to another server, or go back to your home server, is the use of the hive. If you try to log into your home server it will transport you back to the server you logged out on.
3) If you transport to a server and die, you will spawn as a freshie (other than the PVP Deathmatch Server). So be cautious with the gear you transport with.
4) Hive Terminals will have a Beacon on the Map just like the traders. Chernarus is located at Green Mountain, DeerIsle at the Stark Mountain Trader, and Melkart and Pripyat at the Safezone Traders.